Contribution estimate of the 2+(1.78 MeV) level excitation in silicon nucleus to the cross section of the 28Si(π, 3π)28Si * reaction

For the purpose of studying the channel contribution with low-lying level excitation in silicon nucleus into the differential cross section of the reaction the π-+28Si→π-+π-+π++28Si reaction is investigated at the bombarding 16 GeV/c pion momentum. The calculation of differential cross sections on the basis of the Glauber model with a factorizing nucleus density is performed. The found parameters of nuclear densities are tabulated. The investigated reaction differential cross sections are calculated with account of coherent production as well as the channel with 2+(1.78 MeV) level excitation. The calculated differential cross sections values integrated by the effective mass of the produced three-pion system (0.9 GeV<Msub(3π)<1.9 GeV) are presented in the graph form. Integral cross sections of the three-pion production in silicon: σsub(coh)=2.3 mb, σ(2+, 1.78 MeV)=0.25 mb are obtained. It is shown that filling the diffraction minimum in three-pion production differential cross section for ''alive'' silicon target is due to contribution from events with the excitation of the low-lying level 2+(1.78 MeV)